Ph.D. DEFENSE COMMITTEE

Advisor:  Professor Martin Heeney (Chemistry)

Chair:  Professor Shadi Fatayer (Applied Physics)

External Committee Member:  Professor Martyn McLachlan (Imperial College)

Internal Committee Member:  Professor Nikolaos Hadjichristidis (Chemistry)

Abstract

Semiconductors are materials possessing properties between insulators and conductors and are essential in every modern electronic device. Organic semiconductors have advantages such as tunable electronic properties, cost-effective processing, mechanical flexibility, and optical transparency. This makes them highly promising for wearable electronics, photovoltaics, and photodetectors.

Polymer organic semiconductors enable large-scale, high-throughout manufacturing due to their roll-to-roll compatibility. Commonly, conjugated polymers have a so-called alternating structure, combining one electron-donating and one electron-accepting segment in a repeating unit. By manipulating individual units inside alternating structures, a variety of different conjugated polymers with required properties for specific applications can be synthesized.

Our study is focused on the synthesis and study of conjugated polymers for all-polymer organic photovoltaics and organic photodetector electronic devices. While both device types share structural similarities and convert light into charge carriers, photovoltaics store energy for future use, whereas photodetectors generate an immediate electrical signal. The findings include molecular weight dependency of the promising electron-donating polymer and synthesis and characterization of various new polymers for photodetector applications. We hope these insights will boost the understanding and future commercialization of conjugated polymers as semiconductors in electronic devices.